Well pump



March 2, 1965 D, B. HARNEY 3,171,629

WELL PUMP Filed March 14, 1963 a7 5,7 "il y g l'\: 70 5x 7 j i 4o f l h1;, a 54 f 3o f zc f f E 28 oem/ 6. Men/5V BY J 6&1, Mw( M United States Patent O 3,171,629 WELL YUM? Doran B. Harney, Downey, Calif., assigner to Dresser Industries, inc., Dallas, Tex., a corporation of Belaware Filed Mar. i4, 1963, Ser. No. 265,@86 itl laims. {CL 2S3--48) This invention relates generally to fluid driven pumps, and more particularly to fluid turbine-driven centrifugal type pump units for submerged, so-called bottom hole pumping operations within deep wells.

Such fluid driven turbo-pump units, to which this invention relates, employ a fluid reaction turbine and a fluid reaction or centrifugal type pump means coaxially coupled together to form a single compact, minimum diametered unit with the runners of the turbine and the impellers of the pump mounted coaxially on a common shaft. in the installation of such a pumping unit in an earth bore, such as an oil or Water well, it is common practice, if not a practical necessity, to suspend the unit coaxially of the well bore such that the impellers and shaft of the turbine and pump rotate about a substantially vertical axis.

Heretofore, numerous problems have been encountered in constructing such turbo-pump units, particularly for vertical operation as before mentioned, which would operate with satisfactory durability under widely varying turbine power and pumping loading conditions, particularly those encountered within deep wells. Among such difficulties has been that of providing suitable means for rotatably supporting and resisting the axial thrust forces resulting from the dead weight and from the unbalanced axial components of the fluid pressure and reaction forces acting upon the rotatably mounted turbine runner and pump impeller assemblies, under varying operating conditions.

Under normal operating conditions such axial forces may be countersacted or balanced out by means incorporated in the turbo-pump unit, as hereinafter shown and described, which are responsive to the pressure of the power fluid supplied for driving the turbo-pump unit. However, such thrust balancing action is dependent upon maintenance of the pressure of the supplied power fluid within a pressure range bearing a proper relation to the other operating conditions of the pump such as the rotational speed of the turbine and pump elements, pumping head, kind of fluid supplied and pumped, and so on.

Consequently, among the before-mentioned problems has been that of providing means to carry the dead weight and downward forces of the rotating assembly and minimixing wear on the thrust bearings during periods of abnormal operation when the pressure of the power fluid is less than that of falling within the beforementioned pressure range and particularly during the starting up or shutting down of the unit, principally' the latter, when the power fluid is shut ofi and the rotating assembly continues to rotate or coast for a period of time before coming to a standstill. Also under some conditions, where the power fluid pressure, and the character and head of the fluid being pumped, varies or changes abruptly causing surges, the interaction of the hereinbefore mentioned axial thrust balancing mechanism and the axial reaction forces on the runner and impellers may be such as to cause extreme axial excursions and sometimes induces axial oscillations which tend to be self-perpetuating and may increase in amplitude unless damped or checked by suitable means. Unless so damped axial movement of the shaft to the endwise limits of its motion will occur causing the end thrust limiting means to be alternately brought into forceful rotating abutment with each other resulting in excessive wear and eventual destruction thereof, including impair ing the fluid balancing system.

It is therefore, a principal object of this invention to ICC provide means for rotatably supporting the aforesaid weight and axial thrust of the rotating turbo-pump elements and shaft during the periods of operation when the power iluid is unavailable or is of insufficient pressure t0 operate the axial thrust balancing mechanism of the unit.

It is another object of this invention to provide improved means for minimizing wear and damage to the axial thrust supporting means resulting from unbalanced axial weight and thrust of the rotating assembly, particularly that occurring during the starting up and shutting down periods when the rotatable assembly is starting or continuing t0 rotate while power fluid is not available or its pressure is insuilicient for actuation of the weight and thrust balancing mechanism.

It is a still further and particularly important object of this invention to provide a means for preventing or damping out excessive or periodic axial movements of the rotating assembly of the turbo-pump.

It is still another object of this invention to provide improved means for temporarily rotatably supporting the weight of a vertically positioned turbine and pump impeller assembly unit during starting and stopping operations thereof.

It is a further object of this invention to provide improved means for preventing wear and damage to the several impellers of the turbine and pump, which may result from variations in axial positions thereof under varying load and during pump starting and stopping intervals.

These and other objects, advantages and features of novelty will be evident hereinafter.

ln the drawings, which illustrate a preferred embodiment and mode of operation of the invention and in which like reference characters designate the same or similar parts throughout the several views:

FIGURE l is a view, partly in elevation and partly in longitudinal section, of a turbine driven pump unit assembly embodying the present invention and illustrating a manner of installation of the unit in a typical oil well casing.

FIGURE 2 is an enlarged, longitudinal sectional view of the turbine driven pump unit shown in FIGURE l.

FGURE 3 is an enlarged, fragmentary View of the portion of FIGURE 2 indicated Within circle 3.

FIGURE 4 is a fragmentary View of a portion of FlG- URE 3.

Referring rst principally to FIGURE l, a typical well casing is illustrated at lil, having installed on the upper end thereof a typical casing head 12. Within the casing lil and suspended from the casing head 12 upon suitable pipe or tubing lil, as indicated generally at 16, is a turbo-pump unit, containing within it the features of the present invention, The turbo-pump unit lo is of smaller outside diameter than the inside diameter of the casing lil enabling it to be lowered into the casing upon the pipe or tubing 14 in conventional manner to the depth of the well from which the production lluid entering the well is to be lifted. The upper end of the pape or tubing le makes connection through the casing head 12, in conventional manner, to an inlet pipe Ztl, which is in turn connected to a source of power fluid, such as oil, water, gas or the like, which may be supplied under suitable pressure through a fluid circulating pump, not shown.

The annulus lll between the casing l@ and pipe I4 is connected at its upper end through the casing head l2, in conventional manner, to a fluid outlet pipe 22, which is in turn connected to a suitable receiver or storage means which may include means for separating and cleaning the thus received fluid and for returning a part thereof to the before mentioned circulating pump for re-introduction under pressure through connection 20 to serve as the before mentioned power fluid.

The lower `suction inlet end of the turbo-pump unit 16 is coupled at 17 through a wall packer, which is more or less schematically illustrated at 26, to the upper end of a section of conventional strainer or perforated pipe 28 which extends downwardly into the lower portion of the well. Packer 26 which may be of any conventional design, but preferably capable of being set and released in the well casing by manipulation of the suspending pipe or tubing 14, such as for example a conventional slip actuated hook wall production packer, serves to separate the annular space 11a in the lower portion of the well casing into which the strainer or perforated pipe 28 extends, from the annular space 11 in the upper portion containing the turbo-pump unit 16 and suspending pipe 14.

The lower portion of the turbo-pump unit housing 18, indicated generally at 30, contains the centrifugal pump section which receives production ilu-id from the lower portion of the well below the packer 26 through the strainer or perforated pipe 28 and discharges the same therefrom to the exterior of the housing 18 above the packer 26 through a plurality of intermediately located,

circumferentially spaced-apart discharge ports as shown at 32. The upper portion of the turbo-pump unit housing 18, indicated generally at 34, contains the turbine drive section which receives pressure fluid at its upper end through pipe 14 and discharges the same, together with the before mentioned production fluid from the centrifugal pump section, through the same discharge ports 32. The thus commingled fluid discharged through the ports 32 from both the pump section 30 and the turbine section 34 flows upwardly, as indicated by the arrows 36 and 37, through the annular space 11 within the casing to the casi-ng head 12 and thence through the outlet pipe 22 to the storage and separating means, as hereinbefore mentioned.

Referring now primarily to FIGURE 2, the turbopump unit assembly 16 comprises an elongated hollow cylindrical housing 1S, which is closed at its upper end by a turbine inlet head 40 and is closed at its lower end by a pump inlet head 42.

The turbine inlet head 40 is formed with an exterior, upper, cylindrical section 44 having an outside diameter substantially equal to that of the housing 18, an intermediate section 46 of reduced outside diameter having external threads as shown at 48, which make screwed connection with corresponding internal threads 5() in the upper end of the housing 18, and a lower, downwardly extending, skirted sect-ion 52 of ystill further reduced outside diameter. Suitable sealing means, such as an O-ring and groove as shown at 54 is provided between the inside wall surface of the housing 18 and the adjacent outside surface of the intermediate section 46 of the inlet head 40. The turbine inlet head 4G is also provided with a coaxial bore 60 extending partway therethrough from its upper end, the upper end portion of which makes -screwed connection at 61 with the lower end of pipe 14. A plurality of downwardly, divergingly directed inlet passages, as shown at 62, extending through the turbine inlet head 40', interconnect the lower end of the bore 6d with the upper end of an annular space 64 formed between the outer cylindrical surface of the downwardly projecting annular skirted section 52 of the inlet head 4@ and the adjacent inside surface of the housing 18.

The underneath end of the turbine inlet head 46 is also formed with a coaxial, downwardly facing, generally frusto-conical shaped cavity 68, the lowermost internal cylindrical portion of which is bounded by the inner wall of the before mentioned annular skirted section 52. A plurality of obliquely directed outlet ducts, as shown at 70, circumferentially interspaced between the before mentioned passages 62, as shown in FIGURES 1 and 2 extending through the turbine inlet head 40, serve to interconnect the cavity 613 with the exterior of the turbine inlet head 40 at the upper exterior beveled end portion 72 thereof. The uppermost end portion of the frustoconical recess 68 is formed with a downwardly facing, flat bottomed circular recess 74 in which is llushly seated and secured a metal thrust disk 76.

The pump inlet head 42 at thelower end of the housing 18, is formed with an upper internally threaded sleeve portion 96 having an inside diameter slightly less than the outside diameter of the housing 1S, and also with a coaxial bore therethrough having an upper portion 98 of reduced inside diameter relative to the sleeve, thereby forming an upwardly facing annular shoulder 10d, and a lower bore portion 162 of still further reduced inside diameter terminating in an externally threaded connection 103. The upper sleeve portion 96 is provided with internal threads, with which corresponding external threads 56 on the lower end of the housing 1S make screwed coupling connection. An annular lock ring 58 carried on the said external threads 56 on the lower end of the housing 1S is adapted to be screwed into jamming engagement with the top end of the threaded portion 96 of the inlet head and thereby serves to lock the screwed coupling between the pump inlet head 42 and the lower threaded end of the housing 18 in a longitudinally adjustable position relative to one another, as required to clamp the several turbine and pump assemblies axially together within the housing 18, as hereinafter more fully described.

Positioned -within the lower end portion of the housing 1S and seated within the intermediate bore portion 98 of the bore of the pump inlet head 42 is a generally annular, lower retainer body 1M formed with an upper annular portion 166 having an outside diameter slightly less than the inside diameter of the adjacent portion of the housing 18 and with a lower annular end portion 167 of reduced outside diameter, thereby forming at the juncture of the upper portion 1% and the lower portion 107 a downwardly facing annular shoulder 108. The lower end portion 107 makes coupling engagement within the intermediate bore section 9S of the pump inlet head 42, with the downwardly facing annular shoulder 108 thereof seated upon the before mentioned upwardly facing annular shoulder of the pump inlet head 42. An O-ring seal and groove, as shown at 87, is provided between contiguous surfaces of the outside of the upper annular portion 106 of the retainer body 104i and the inside surface of the housing 18. A set screw 110 threaded through the wall of the pump inlet head 42 into engagement at its inner end with a drilled recess 111 in the lower retainer body 104 serves to lock the said retainer body rmly seated and free of axial and rotational movement within the pump inlet head 42.

The annular lower retainer body 1&4 is provided with a coaxial bore extending therethrough, said bore having an upper, upwardly converging, frusto-conical portion 112, and a lower cylindrical portion 114. Supported within the lower cylindrical bore portion 114 of the lower retainer body 164, by means of a spider structure comprising a plurality of radially extending, integrally formed web members as shown at 116, is a central, coaxially located, cylindrical shaped bearing housing 11S. Press fitted within the bearing housing 118 is a sleeve bushing 120, which constitutes a bearing for the lower end of the turbine and pump drive shaft 122.

Coaxially coupled and seated upwardly within the lower portion of the skirted section 52 of the turbine inlet head 40 is a generally annular shaped upper retainer body 80 having a coaxial bore S2, and formed with an outer upper end portion 84 of reduced outside diameter, which extends into said coupling engagement with the inside of skirted section 52. An O-ring seal and groove, as shown at 86, is provided between the contiguous cylindrical surfaces of the skirted portion of the upper end portion S4. As best shown in FGURE 3 the bore 82 of the annular upper retainer body 86 has fixed therein a sleeve shaped bearing liner 8S, said liner 3S having intergrally formed at its upper end a radially outwardly extendng flange dit which seats upon the annular, upper end surface of the upper retainer body Sd. The inner cylindrical surface of the bearing liner titi is formed with a plurality of axially spaced-apart, semicircular sectioned, inwardly facing annular grooves, as shown at 92.

Contained within the upper retainer body Sti in circumferentially spaced-apart arrangement encircling the bore S2 thereof are a plurality, not less than three, and preferably four or more, rotor supporting and damping assemblies indicated genera ly at Ztlt. As best shown in FIGURE 3 each of the rotor supporting and damping assemblies 253@ includes and is mainly contained within a bore shown generally at extending axially through the retainer body 3h from the lower to the upper end thereof. The bore 2h21 is formed with a lowermost portion Ztl-l of maximum inside diameter entering the lower side or the retainer body Si?, a lower interi ediate threaded portion flle, an upper intermediate bore portion El@ of slightly reduced inside diameter and an uppermost portion 212 of substantially reduced inside diameter opening through the upper end of the retainer body Sti and extending through the flange 9@ of the bearing liner S8.

Axially slidably retained coaxially within the bore portion Edt) is a supporting plunger formed with a lower cylindrical piston 2Std, an upper flat topped head 21d and an interconnecting rod member 22d. The piston Zld is slidable axiallly between limits within the upper intermediate portion of the bore 2&2, and the rod member .22@ is axially slldable and extends upwardly therefrom through the upper portion 212 of the bore, the head 2l thereon normally being positioned a short distance above the upper surface or" the beari g flange Sill. rfhe plunger assembly is urged upwardly by means of a helical spring 222 acting under compression between the bottom surface of the piston Qld and the upper end of a threaded plug 224i which is inserted upwardly through the lower portion 294 ofthe bore 2h22 and received into the threaded portion 2%. An @ning seal and groove as shown at encircles the plunger rod ft, and a small vent duct 23) extends through the upper portion of the upper retainer body dll for restricted communication between the cavity 68 andthe upper end ofthe bore 2lb. The inside diameter' of the bore portion di? and the outside diameter of the piston 2id therein is such as to provide only sliht clearance therebetween, whereby when the bore surrounding the piston is filled with fluid which enters through the duct 23d, the piston can be moved axially therein, but will forcefully resist such motion, particularly rapid motion, thereby imparting the characteristics of a dash-pot 'to the supporting and damping assemblies Rotatably and longitudinally slidably contained Within the hereinbefore described sleeve shaped bearin7 liner 3S contained within the upper retainer body Sli is an annular shaped, combined shaft bearing and plunger member 124 having integrally formed at its upper end a coaxial, radially outwardly extending flange member or balancing disk E26, the outside diameter of which is greater than that of the annular plunger member 12d, but less than the inside diameter of the adjacent walls of the cavity 68. The peripheral, marginal portion of the balancing disk 126 is formed with a downwardly depending annular rim t28 which normally, under non operating conditions, rests upon and is supported by the upper surface of the radial flange portion 90 of the bearing liner 88.

The annular plunger member 12d is provided with a coaxial bore therethrough, the major section 127 of which has an inside diameter substantially greater than that of an upper end section 13), located centrally of the balancing disk 1.26, thereby forming at the juncture of such upper and lower bore sections a downwardly facing, annular shoulder 132 located coaxially of the before mentioned balancing disk E6. The upper end of the shaft l22 is formed with an upwardly extending attachment portion 134 of reduced outside diameter and carrying external threads i3d adjacent its upper end. The upper end portion of the shaft lZZ extends into and is xed within the bore 1.27 in abutment with the before mentioned downwardly facing shoulder 132 and with the upwardly extending attachment portion 134 of reduced diameter extending through the bore B0 in the balancing disk 12e. An annular nut 123 threaded on the shaft threads 136 serves to retain the integral plunger member and balancing disk 12d, 126 firmly attached to the upper end of the shaft 1.22. The plunger member 24 is keyed to the shaft 122, as shown at 12S.

Contained coaxially within the housing 1S between the upper annular retainer body t? and the lower annular retainer body 64, is a plurality of coaxial turbine drive stages and centrifugal pump stages, which generally occupy the upper and lower portions of .the turbo-pump unit indicated at 35i and Fati, respectively. For convenience of illustration, three turbine stages, located and indicated generally at T1, T2, and T3, and three centrifugal pump stages, located and indicated generally at P1, P2, and P3 have been shown and described herein. However, a greater or lesser number of such stages in either or both the turbine section and pump section may be employed, the choice being dependent upon various factors of a particular installation such as, for example, the available differential pressure, quantity and kind of driving fluid, and the pumping head, volume aud kind of fluid required to be handled by the pumping unit.

Each of the turbine drive stages comprises in brief, with reference mainly to turbine stage T2 as being typical, a turbine stator or cover body comprising an upper annular cover plate 140, a lower annular base plate M2, and an intermediate annular separator member E44-, all preferably integrally formed in a single casting. Between the outer marginal portion of the intermediate annular separator member ldd and the annular base plate x42 is a vaned diffuser section 3148 for directing flow of the power fluid laterally inwardly into the runner, as i-ndicated by the arrow therein. Between the annular cover plate le@ and the intermediate separator member 144 is formed a radially vaned, annular passage ldd for flow of fluid discharged from the preceding stage to the diffuser section i158, as indicated by the arrow therein. An O-ring seal and groove as shown at l@ is provided around the outer periphery of each cover plate of each turbine cover body, making sealing engagement with the inside surface of the housing l.

Rotatably contained within a generally cylindrical cavity formed within the diffuser section of the turbine cover body is an internally varied, turbine runner 15d of the mixed flow type, adapted to receive power fluid radially and to discharge same axially. The runner 15) is secured to the shaft lZZ by means of a tapered locking sleeve l?, which is press fitted between the bore of the hub 154- of the runner 15! and the cylindrical surface of the shaft 22.. The runner hub ld extends upwardly into yand makes a relatively free rotatable tit within the circular opening in the center of the before mentioned intermediate annular separator member M4 of the cover bod".

The turbine runner 15d is formed with a coaxial, downwardly extending, axial discharge sleeve 15d which, like the hub, makes a relatively free rotatable lit within a central, circular opening in the annular cover plate lltla of the next adjacent lower turbine stator cover body. Each of the runners is formed with an exterior, radially extending, downwardly facing, annular bearing surface as shown at 153, adapted under certain operating conditions, as hereinafter described, to make supporting engagement with the adjacent upper surface of the before mentioned cover member ltla of the next adjacent lower turbine cover body.

Each of the centrifugal pump stages has a construc- Y tion which is similar to that of the hereinbefore described turbine drive stages, except that the vanes of the impeller and the diffuser sections in general may be shaped slightly diiferently, as is well known in the art, to provide for the proper direction of flow of pumped fluid therethrough in a relative direction opposite to that of the flow of liuid in the turbine drive stages, such ilow in the pump stages and turbine drive stages being indicated by the several arrows. As hereinbeore mentioned, the fluid discharged from the final stage of the turbine drive, which is that leaving the discharge of the runner of the turbine stage T3, and the fluid discharged froin the final pump section, which is that discharged from the impeller through the diifuser section of pump stage P3, commingle within the adjacent portion of the housing 18 and are discharged directly therefrom through the ports 32 into the annular space intermediate the housing 18 and the casing 10, and thence ilow up through said annular space to the casing head 12 and out through the outlet pipe 22, as hereinbefore mentioned.

The several turbine drive and centrifugal pump stator case or cover body units are coaxially nested together, one upon another, and pin connected together as shown at 174, against relative rotation thereof, and such cover body units are clamped together axially by means and between the upper annular retainer body S and the lower annular retainer body 104. These retainer bodies are, in turn clamped together by adjustment of the coupling of the threaded connection between the lower end of the housing 18 and the pump inlet head 42. The hereinbefore described lock ring S serves to maintain such clamping adjustment.

In operation of the apparatus of the invention, power fluid is forced under suitable pressure down the tubing or pipe 14 to the upper end of the turbine pump unit 16 where it passes through the inlet passages 62 into the ananular space 64 within the housing 18. From the annular space 64, the power iiuid flows under pressure through the diffuser section radially inwardly into the passages in the runner of the iirst turbine drive stage T1 from which it is discharged axially downwardly into the passage 146 of the cover body of the second turbine drive stage T2. From the passage 146, iiuid under pressure flows around the edge of the separator member 144 and radially inwardly through the diffuser section 148 into the vaned passages of the runner of the second stage turbine drive T3. The pressure fluid discharged axially downwardly from the runner of the second stage turbine drive iiows outwiardly through the adjacent passage, through the diffuser section and radially inwardly into the runner of the third turbine drive stage T3, in the same manner as that hereinbefore described. The power uid finally discharged from the runner of the third turbine drive stage T3 iiows outwardly through the discharge ports 32, as hereinbefore mentioned.

Production fluid which has entered the bottom of the casing 10, ows in through the openings in the strainer pipe 28 and iills the passages within the centrifugal pump section of the housing 18. Rotation of the pump impellers by the turbine drive then causes the production fluid to be drawn in through the strainer pipe 28 and up into the central inlet of the impeller of the irst pump stage P1 from which it is discharged into the passages of the vaned cover body thereof and thence flows into the central inlet of the impeller of the second pump stage P3 and so on until it is discharged from the third centrifugal pump stage P3 and out through the before mentioned discharge passages 32.

The power fluid discharged from the last stage T3 of the turbine drive and the production fluid from the last stage P3 of the pump section commingles as they are discharged through the openings 32 in the housing 18 into the annular space in the casing and from there the commingled power fluid and pumped production iiuid iiows upwardly through the annular space in the casing to the casing head 12 and thence is discharged through the outlet pipe 22 to the storage and separating means, as hereinbefore mentioned.

Because of the axial forces acting upon the several runners of the turbine drive stages and the impellers of the centrifugal pump stages resulting from the pressure differentials and dynamic forces of the iiuids flowing therethrough which are seldom, if ever, in exact balance with each other, the whole rotating system including the shaft 122 is usually subjected to resultant axial forces, which tends to displace it and the rotors and impellers carried thereby axially relative to the turbine and pump cover bodies and housing. This axial force during normal running conditions must be resisted by some means which is reiatively free from friction and wear and which will automatically compensate for changes in the axial forces, resulting from changes and variations in pumping conditions. Such means must also automatically maintain the proper axial position of the shaft 122 and the impellers and runners relative to the structural members of their surrounding cover bodies, otherwise ineicient running conditions will occur and even in extreme cases possible damage or destruction of the runners and impellers may result.

Usually, under normal operating conditions, the resultant axial force in the shaft 122 is downward relative to the stationary portions of the apparatus, and relatively friction free, automatic compensation for this downward force is accomplished as follows.

Suiiicient clearance is provided at the outer edge and along the upper portion of the runner of the first stage turbine drive T1 to permit pressure iluid from the diffuser to flow under pressure between the top of the runner and the bottom of the annular retainer body 80, and thence into the space surrounding the drive shaft 122 at the lower end of the annular plunger member 124. The clearance between the outside diameter of the plunger member 124 and the inside diameter of the bearing sleeve 83, which may be approximatey 0.006 is suiiicient to permit flow of a relatively small quantity of pressure iiuid therethrough into the annular space 170 formed under the balancing disk 126 within the rim 12S. The differential pressure thus established across the annular plunger 124 and the balancing disk 126 tends to lift the drive shaft 122 axially upwardly suficient to balance the otherwise unbalanced downward axial forces therein. As the balancing disk 126 is thus lifted, the lower edge of the rim 12S is raised out of sealing contact with the upper surface of the bearing flange 90, thereby permitting escape of a small quantity of pressure fluid from space 170 into the cavity 68, thereby causing a small drop in the pressure -acting on the area under the balancing disk 126. This action continues until equilibrium is reached between the fluid pressure acting upwardly on the plunger 124 and the balancing disk 126 and the downward force transmitted thereto bythe shaft 122, and under such conditions of equilibrium, the lower edge of the rim 128 of the balancing disk 126 will iioat a short distance above and out of contact with the upper `surface of the bearing flange as illustrated in somewhat exaggerated scale in FIG- URE 4, and the under surface of the balancing disk on the upper side of the cavity will be positioned out of Contact with the top surface ofthe heads 216 of the damping assemblies 200.

The pressure fluid which escapes into the cavity 68 is exhausted through the passages 70 into the annular space betweenthe casing 10 and pipe 14 at the upper beveled surface 72 of the turbine inlet head 40.

As hereinbefore mentioned, pressure fluid will also enter through the duct 230 and iill the spaces in the bore 210 surrounding the piston 214 and rod 220. In event of any abnormally great axial movement of the rotating system, the undersurface of the balancing disk 126 within the cavity 170 will be brought downward into contact with the top surface of the plunger head 236, thereby applying a force through .the rod 22d to the piston 214 tending to move it downwardly within the bore 2li) against the force of spring 222, such movement also being resisted by the dash-pot `action resulting from the displacement of fluid from the lower end of the bore 2l() past the clearance spaces 'around the piston 2M into the upper end of the bore 210. A damping impulse is thu-s applied through the disk 12o to the rotating system each time 'the axial displacement thereof is suieient to bring the damping assemblies into action. Any tendency for the rotating system to build up continuous, periodic, axial oscillations or displacements will be checked or damped out by this action.

Upon shutting oli the supply of Ipower lluid for the purpose of shutting down the turbo-pump unit, the axial thrust balancing features of this apparatus which are dependent upon the pressure fluid for their operation is immediately rendered ineffective, and then, except for the action of the damping assemblies 2W, the rotating lassembly of the unit would immediately drop from its equilibrium operating position shown in FGURE 4 to that shown in FGURE 3 whereupon the under surface of the flange 12S of the supporting disk 126 would be brought into forceful, frictional engagement with the top surface of the bearing ange Nl, resulting in its wear and possibly damage. However, such action is prevented by the damping assembly Zut), which instead of permitting the rotating assembly to drop, follow-ing shut oli of the power i'luid, initially permits it to drop only sufficiently lto bring the underside of the supporting Jlange 126 into supporting Contact with the top of the plunger heads 21o. Then by reason of the dash-pot action of the piston 2l4 in the iluid tilled bore Zltl, the supporting flange 126 and the rotating assembly supported thereby is only permitted to lower slowly from the position shown in FIGURE 4 to that shown in FlGURE 3 during which lowering time, the rotation of the rotating assemly 'has time to come to a standstill and during which time, substantially all of lthe frictional forces which would cause wear would be taken by and absorbed at the interface between the top surface of the plunger head 216 and the under surface of the supporting disk 126.

Upon starting up the unit from a standstill, the action would be substantially the reverse of that for the shutting down operation except that the action of the plunger under the force of .the helical spring would be such las to assist in the initial liftlnv of the rotating system from that shown at FGURE 3 to that of FIGURE 4, thus shortening the period of time in which the lower surface of the ange 12S of the supporting disk jtZo would be in rotational frictional engagement with the top surface of the flange 7G of the sleeve bearing S8. Progressive wear thus occurrinfr on these parts is of minor consequence, does not cause any impairment of the operation of the unit, and such parts can be replaced in much less time and at less expense than would be the case with other parts of the unit.

it is 'to be understood that the foregoing is illustrative only `and that the invention is not limited thereby, but may include various modications and changes made by those skilled in the art within the scope of the invention as delined in the appended claims.

I claim:

l. ln a turbo-pump apparatus lfor installation in wells having a housing adapted to be lowered into a well, rotata'ole fluid reac ion means in said housing rfor tlow of fluid therethrough, including shaft means on which said reaction means is ixed for rotation therewith, said shaft in operation being free for limited movement axially relative to said housing, means for damping such axial movement comprising:

a cylinder bore in said housing;

a piston axially reciprocally contained in said bore,

Said bore bein.cr adapted to contain a iiuid for lOilerl@ ing resistance to axial movement of said piston therein;

and means responsive to axial movement of said shaft in excess of a predetermined amount from a predetermined axial position, for movement of said piston in said cylinder, whereby resistance may be offered to movement of said shaft in excess of said pred-etermined amount.

2. In a turbo-pump apparatus for installation in wells having a housing adapted to be lowered into a well, rotatable lluid reaction means in said housing for flow of lluid therethrough, and shaft means on which said relaction means is iixed for rotation about and limited movemen-t axially along a common axis, means for damping Such axial movement comprising:

a cylinder bore in said housing, one end at least of said lbore being substantially closed;

a piston axially yreciproca-bly contained in said bore, there being provision for restricted passage of fluid `from end-to-end of said bore past said piston;

means for introducing fluid into said bore, whereby said iluid may olier resistance to axial move-ment yol? said piston therein;

and means responsive to axial movement of said shaft in excess of a predetermined amount for movement of said piston in said vcylinder whereby resistance may be offered to movement of said shaft beyond vsaid predetermined amount.

3. ln 4a turbo-pump apparatus for installation in wells having Va housing adapted to ibe lowered into a well, rotatable lluid reaction means in y.sa-id housing for llow of fluid therethrough, inlet passage means for introducing fluid into said housing and to said rotatable reaction means, :and shaft means on which said reaction means is xed for rotation about, and limited movement axially along a common axis relative to said housing, means for damping such axial movement comprising:

a cylinder bore in said Ihousing one end at least of said bore being substantially closed;

`a piston axially reciprocably contained in said bore, there being means `for restricted passage of lluid from end-to-end of said bore past said piston;

means communicating with said inlet passage means for introducing fluid into said bore, whereby said fluid 4may offer resistance .to 'axial movement of said piston therein;

and lost motion means respon-sive to axial movement of said said shaft in excess of a predetermined amount for movement of said piston in said cylinder whereby resistance may be offered to movement of said shaft beyond said predetermined amount.

4. In a turbo-pump apparatus for installation in wells having -a housing adapted to be lowered into a well, a rotatable Huid reaction means in said housing for tlow ot liuid therethrough, and shaft means on which said reaction means is lxed for rotation about and limited movement axially long a common axis in sai-d housing, means for damping such axial movement comprising:

a cylinder bore in said housing;

piston means axially reciprocably contained in said bore;

means for introducing fluid into said bore for offering resistance to axial movement of said piston means therein;

and means responsive to axial movement of said shaft in excess of a predetermined amount from a predetermined position, for movement of said piston in said cylinder whereby said resistance to axial movement may be applied to movement of said shaft beyond said predetermined amount.

5. In a turbo-pump apparatus for installation in wells having 4a housing adapted to be lowered into a well, rotatable fluid reaction means in said housing for ow of :duid therethrough, and shaft means on which said reaction means is fixed for rotation about and limited moveil ment axi-ally along a common axis, means for damping such axial movement comprising:

a plurality of cylinder bores circumferentially spacedapart in said housing around the axis of said shaft, at least one end of each of said cylinder bores being substantially closed;

a piston axially reciprocably contained in each of said bores, there being means for restricting passage of fluid from end-to-end of each of said bores past each t of said pistons whereby such fluid may offer resistance to such movement of said pistons in said bores;

Y a laterally extending actuating means fixed to said shaft and axially movable therewith, said actuating means having a laterally extending, axially facing surface;

a plunger axially extending through the end of each of said bores from each of said pistons with the outer end of each of said plungers adjacent to but in normal operation in a position spaced from contact with said axially facing surface, whereby axiai movement of said shaft and said actuating means in excess of a predetermined amount from said position moves said :surface into contact with said outer ends of said plungers, whereby resistance may be offered to such movement of said shaft in excess of said predetermined amount.

6. In turbo-pump apparatus for installation in wells having a housing adapted to be lowered into a well, rotatable fluid reaction means in said housing for ow of iiuid therethrough, inlet passage means for introducing fluid under pressure into said housing for driving said rotatable reaction means, and having vertical shaft means on which said reaction means is fixed for rotation therewith, said shaft in operation being free for limited movement axially relative .to said housing, apparatus comprising:

fluid pressure operated supporting means operative by and during said introduction of said iiuid under pressure for supporting said shaft vertically at a predetermined vertical position relative to said housing during operation, said supporting means being ineffective upon discontinuance of said introduction of said fluid under pressure, whereby said shaft tends to drop vertically from said predetermined position;

a cylinder bore in said housing;

a piston axially reciprocably contained in said bore, whereby resistance is offered to axial movement of said piston therein;

and lost motion means responsive upon the dropping of said shaft a predetermined distance below said predetermined position for moving said piston in said cylinder, whereby resistance is offered to such dropping movement of said shaft below said predetermined distance.

7. In la turbo-pump apparatus for installation in wells having a housing adapted to be lowered into a well, rotatable fluid reaction means in said housing for flow of iiuid therethrough, inlet passage means for introducing power uid under pressure into said housing for driving said rotatable reaction means, and having vertical shaft means on which said reaction means is fixed for rotation therewith, said shaft in operation being free for limited movement axially relative to said housing, apparatus comprising:

fluid pressure actuated means operated by and during said introduction of said power fluid for supporting said shaft at a predetermined vertical position relativeto said housing during the driving of said rotatable reaction means, said supporting means being ineffective upon discontinuance of said introduction of said power fluid whereby said shaft tends -to drop vertically from said predetermined position;

' a flange fixed to said shaft and having a downwardly facing annular surface;

a plurality of parallel plungers circumferentially spacedapart in said housing about the axis of said shaft i 12 below said ange, vsaid downwardly facing annular surface thereof being positioned adjacent to but spaced from the upper ends of said plungers while said shaft is supported at said predetermined position during operation, but being lowered into rotating engagement with the said upper ends of said plungers upon the dropping of said shaft from said predetermined position;

whereby the friction and Wear of continued rotation of said shaft after said discontinuance of said introduction of said iiuid under pressure, is absorbed by the mutually contacting surfaces of said fiange and the upper ends of said plungers.

8. In a turbo-pump apparatus for installation in wells having a housing adapted to be lowered into a well, rotatable fluid reaction means in said housing for flow of iiuid therethrough, inlet passage means for introducing power uid under pressure into said housing for driving said rotatable reaction means, and having vertical shaft means on which said reaction means is fixed for rotation therewith, said shaft in operation being free for limited movement axially relative to said housing, apparatus comprising:

fluid pressure actuated means operated by and during said introduction of said power iiuid for supporting said shaft at a predetermined vertical position relative to said housing during the driving of said rotatable reaction means, said supporting means being ineffective upon discontinuance of said introduction of said power uid whereby said shaft tends to drop vertically from said predetermined position;

a flange fixed to said shaft and having a downwardly facing annular surface;

j a plurality of vertically extending plungers circumferentially spaced apart about the axis of said shaft below said iiange, means supporting said plungers in said housing with limited freedom for vertical sliding movement;

resilient means urging said plunger upwardly toward Y the upper limits of said sliding movement;

said downwardly facing annular surface of said flange being positioned adjacent to but spaced from the upper ends of said plungers while said plungers are positioned in said upper limits of their sliding movement and while said shaft is supported at said predetermined position during operation, but said surface of said flange being lowered into sliding engagement with the said upper ends of said plungers upon the dropping of said shaft from said predetermined position,

whereby the said shaft, after said discontinuance of said introduction of said fluid under pressure, is resiliently supported upon the upper ends of said plungers.

9. In a turbo-pump apparatus for installation in wells having a housing adapted to be lowered into a well, rotatable fluid reaction means in said housing for ow of fiuid therethrough, inlet passage means for introducing power fluid under pressure into said housing for driving said rotatable reaction means; and having vertical shaft means on which said reaction means is fixed for rotation therewith, said shaft in operation being free for limited movement axially relative to said housing, apparatus comprising:

fiuid pressure actuated means operated by and during said introduction of said power iiuid for supporting said shaft at a predetermined vertical position relative to said housing during the driving of said rotatable reaction means, said supporting means being ineffective upon discontinuance of said introduction of said power uid whereby said shaft tends to drop vertically from said predetermined position;

a plurality of plunger means circumferentially spaced apart in said housing about the axis of said shaft,

i3 the axes of said plungers being parallel with the axis of said shaft means;

cylinder means in said housing in which each of said plunger means is axially slidably supported, said cylinder means being adapted to contain fluid for resisting axial motion of said plunger therein;

a ange fixed to said shaft and having a downwardly facing annular surface, said downwardly facing annular surface being positioned adjacent to but spaced from the upper ends of said plungers while said shaft is supported at said predetermined position during operation, but being lowered into rotating engagement with the said upper ends of said plungers upon the dropping of said shaft from said predetermined position;

whereby downward motion of said shaft after said discontinuance of said introduction of said uid under pressure, is checked by the action of said plunger means in said cylinder means.

10. In a turbo-pump apparatus for installation in wells having a housing adapted to be lowered into a well, rotatable iuid reaction means in said housing for flow of fluid therethrough, inlet passage means for introducing power tluid under pressure into said housing for driving said rotatable reaction means; and having vertical shaft means on which said reaction means is fixed for rotation therewith, said shaft in operation being free for limited movement axially relative to said housing, apparatus comprising:

duid pressure actuated means operated by and during said introduction of said power fluid for supporting said shaft at a predetermined vertical position relative to said housing during the driving of said rotatable reaction means, said supporting means being LAURENCE V. EFNER, Primary Examiner. JOSfPH H. BRANSON, IR., Examiner.

i4 ineffective upon discontinuance of said introduction of said power fluid whereby said shaft tends to drop vertically from said predetermined position;

a plurality or plunger means circumferentially spacedapart in said housing about the axis of said shaft, the axes of said plungers being parallel with the axis of said shaft means;

cylinder means in said housing in which each of said plunger means is axially slidably supported, said cylinder means being adapted to contain fluid for resisting axial motion of said plungers therein;

resilient means in said cylinder means urging said plunger means upwardly therein;

a liange fixed to said shaft and having a downwardly whereby downward motion of said shaft after said discontinuance of said introduction or said uid under pressure is checked by the action of said plunger means in said cylinder means.

References Cited by the Examiner UNITED STATES PATENTS 11/12 Griessmann et al 103-112 9/33 Doyle 103-112 

1. IN A TURBO-PUMP APPARATUS FOR INSTALLATION IN WELLS HAVING A HOUSING ADAPTED TO BE LOWERED INTO A WELL, ROTATABLE FLUID REACTION MEANS IN SAID HOUSING FOR FLOW OF FLUID THERETHROUGH, INCLUDING SHAFT MEANS ON WHICH SAID REACTION MEANS IS FIXED FOR ROTATION THEREWITH, SAID SHAFT IN OPERATION BEING FREE FOR LIMITED MOVEMENT AXIALLY RELATIVE TO SAID HOUSING, MEANS FOR DAMPING SUCH AXIAL MOVEMENT COMPRISING; A CYLINDER BORE IN SAID HOUSING; A PISTON AXIALLY RECIPROCALLY CONTAINED IN SAID BORE, SAID BORE BEING ADAPTED TO CONTAIN A FLUID FOR AFFERING RESISTANCE TO AXIAL MOVEMENT OF SAID PISTON THEREIN; AND MEANS RESPONSIVE TO AXIAL MOVEMENT OF SAID SHAFT IN EXCESS OF A PREDETERMINED AMOUNT FROM A PREDETERMINED AXIAL POSITION, FOR MOVEMENT OF SAID PISTON IN SAID CYLINDER, WHEREBY RESISTANCE MAY BE OFFERED TO MOVEMENT OF SAID SHAFT IN EXCESS OF SAID PREDETERMINED AMOUNT. 